*************************************************************************
* Generate a panel with 2007 & 2012 naics code, 1990-2016
*************************************************************************

* 1. import all NAICS code
import excel using "$crosswalks/2012_to_2007_NAICS.xls", cellrange(A3:D617) firstrow clear
rename C naics2007
rename NAICSCode naics2012
rename NAICSTitle industryname2012
rename NAICSTitleandspecificp industryname2007
drop if naics2007>= 400000
drop if naics2007< 300000
sum
order naics2007 naics2012 industryname2007 industryname2012

* 334119 corresponds to 333316 & 334118. I decide to drop the first. 
* Graphs of the analysis behind this decision is generated in the Appendix section of this code
drop if naics2007 == 334119 & naics2012 == 333316
